Square footage calculator
Calculator
The calculator needs JavaScript. The tables below give the same numbers for common cases.
How it is worked out
- Area of each rectangle = length × width; add them up.
- 1 square foot = 0.09290304 square metres (exact), 1 square yard = 9 square feet, 1 acre = 43,560 square feet.
| Inputs | Answer |
|---|---|
| Units: Feet; Rooms or areas, one per line as length x width: 12x14 10x10 8x6.5 | The total area is 320 square feet (29.73 square metres). |
| Units: Metres; Rooms or areas, one per line as length x width: 5x4 | The total area is 215.28 square feet (20 square metres). |
| Units: Feet; Rooms or areas, one per line as length x width: 20x30 | The total area is 600 square feet (55.74 square metres). |
How to use it
Square footage is length × width in feet. For an L-shaped or multi-room space, list each rectangle on its own line and the calculator adds them. It also converts the total to square metres (1 ft² = 0.09290304 m², exact), square yards (9 ft² each) and acres (43,560 ft²).
Measure walls inside, from baseboard to baseboard, and round to the nearest inch for flooring or paint estimates.
Frequently asked questions
How do I calculate square footage?
Multiply length by width, both in feet.
How do I measure an L-shaped room?
Split it into rectangles, calculate each and add them.
How many square feet is an acre?
43,560.
Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.
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General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.